This invention relates generally to exhaust distribution systems and more particularly to systems for exhausting fumes from motor vehicles having vertically oriented exhaust stacks which such vehicles are located within a building having the system in place.
The prior art includes many vehicle exhaust distribution systems for disposition in a building to vent exhaust fumes from automobiles, emergency vehicles, trucks and other vehicles while the vehicle is located therein. While these prior art systems may achieve their intended purpose of venting the exhaust fumes from the vehicle out of the building, they nevertheless suffer from one or more drawbacks. For example, many of these systems are quite complicated and involve many moving parts therefore making installation and maintenance very expensive. Further, many of these systems require manual connection and/or disconnection from the vehicle exhaust stack or tailpipe. Additionally, many of these systems require the placement of a special adaptor or cone over the open end of the vehicle exhaust stack in order to introduce the stack into the exhaust distribution system. Finally, many of these systems use seals, moldings or lips for containing exhaust fumes.
In particular, U.S. Pat. No. 3,473,462 (Imming) discloses an exhaust system wherein a flexible exhaust tube is telescoped when not in use within a rigid storage conduit suspended from the ceiling and communicating with an exhaust fan. The flexible exhaust tube is manually withdrawn from stored position by means of pulleys and cables. The outer end of the flexible exhaust tube is provided with an adaptor which is designed to be fitted over and connected to the end of the vehicle's exhaust pipe. Although the system provides a means for venting exhaust fumes from a tailpipe to the atmosphere outside the building, the above-mentioned drawbacks still appear to exist.
U.S. Pat. No. 4,102,254 (Grant) discloses an exhaust disposal system which includes conduit disposed in a trench below a garage floor which at one end has attached a flexible ribbed cup-like member which is designed to engage with the tailpipe of a vehicle. The conduit can be extended upwardly from the trench by means of a switch activated motor in a manner so that the flexible ribbed cup-like member can engage with the tailpipe of the vehicle and vent exhaust fumes to the outside atmosphere. Although this system provides a means for automatically engaging and disengaging the vehicle's tailpipe, several of the previously mentioned drawbacks still appear to exist. Specifically, this system requires the attachment of a special L-shaped tube to the tailpipe to facilitate engagement with the exhaust disposal system. Further, this system utilizes a moving conduit which is operated by motor consisting of several moving parts, such as a belt and gears.
U.S. Pat. No. 4,567,817 (Fleischer) discloses an exhaust-gas offtake track for exhausting fumes from a track-guided vehicle. The exhaust stack of the vehicle extends vertically into a collecting funnel. The funnel forms a portion of a trolley assembly to slide down the track and communicates with the interior of the track to carry fumes from the vehicle into the interior of the track for venting out of the building. This system also appears to have several drawbacks, namely, the necessity of attaching a collecting funnel to the top of a vertical exhaust stack prior to introducing the exhaust stack into the system, and the necessity to use sealing lips on the underside of the gas waste duct.
It is believed that Filterclean Corporation of Edison, N.J. offers an exhaust distribution system including a venting device for vehicles equipped with vertical exhaust stacks under the model designation VSR-20. It is believed that such a system is arranged for use with vehicles having a vertically extending exhaust pipe and includes a suction rail containing a slit on its bottom side to allow for the introduction of a vehicle's vertical exhaust stack into the exhaust disposal system.
This system is also believed to make use of two rubber sealing lips which run the length of the suction rail to prevent leakage of exhaust fumes to the interior of the structure. In addition, it is believed that the vehicle's vertical exhaust stack must be fitted with a special cone to allow smooth entry into the rubber seals underneath the suction rail.
Other devices which vent and/or trap exhaust fumes from a vehicle's exhaust stack or tailpipe are disclosed in U.S. Pat. No. 4,796,520 (Kramer), U.S. Pat. No. 4,660,465 (Jentzsch et. al.), U.S. Pat. No. 4,259,897 (Nederman), U.S. Pat. No. 4,233,889 (Nederman), U.S. Pat. No. 4,762,054 (Melville et. al), U.S. Pat. No. 4,699,046 (Bellieni) U.S. Pat. No. 4,389,923 (Ludscheidt), U.S. Pat. No. 4,312,645 (Mavros et al.) and U.S. Pat. No. 4,335,574 (Sato, et al.).
While the foregoing prior art systems may achieve their intended purpose, namely, venting the exhaust fumes from the vehicle out of the building, they nevertheless leave much to be desired from the various standpoints previously discussed.
In U.S. Pat. No. 5,092,228 (Pfeiffer)--which is hereinafter referred to as the '228 patent and of which I am a coinventor--there is disclosed and claimed an exhaust distribution system which overcomes many of the drawbacks of the prior art systems. Specifically, the exhaust distribution system of the '228 patent is arranged for use within a structure, e.g., a firehouse, adjacent a space in which a vehicle, e.g., a fire truck, having a vertically oriented, open ended, exhaust stack is to be located. The system basically comprises elongated track mounted horizontally below the ceiling or roof of the structure, a trolley slidably mounted on the track and including an inlet adapted to receive the open upper end of the vertical exhaust stack, a biasing assembly to position the trolley, a blower for venting fumes from the structure, a flexible hose connecting the inlet of the trolley to the blower, and a blower actuating switch for turning the blower when the vehicle's engine is on. The track supports the trolley for slidable movement therealong from a first position adjacent an entrance to the structure to a second position within the structure remote from the entrance and where the vehicle will be parked. The biasing assembly is arranged for automatically positioning the trolley means at the first position so that when the vehicle is driven into the structure the stack is automatically received within the inlet of the trolley and remains in the inlet while the vehicle is within the structure. The blower actuating switch is arranged to sense a predetermined pressure in the stack, thereby indicating that the vehicle's engine is running and exhaust fumes are being produced, to cause the blower to turn on, whereupon the exhaust fumes are drawn through the hose means and the blower to be vented out of the structure.
The system subject to the '228 patent overcomes many of the disadvantages of the prior art systems. For example, one advantage the '228 system has over the prior art is that it is arranged to automatically attach and detach to the open end of the vehicle's stack to discharge any exhaust fumes out of the structure. Therefore, the system does not require manual connection and/or disconnection from the vehicle exhaust stack or tailpipe as is necessary in some prior art systems. Moreover, many of the prior art systems require the use of a special adaptor or cone which is mounted on the open end of the vehicle exhaust stack in order to introduce the stack into the system. In the system of the '228 patent no special adapters or cones are used on the exhaust stack itself. Instead, the open end of the vehicle's exhaust stack enters directly into the mouth of a hose assembly which is supported by a trolley. Further, the prior art systems make use of sealing lips to prevent leakage of exhaust fumes to the interior of the structure. The system of the '228 patent is constructed to enable the open end of the exhaust stack to be fully contained within the inlet end of the hose as the vehicle is moved within the building so that the trolley is moved down the track by the movement of the vehicle.
While the system of the '228 patent overcomes many of the disadvantages of the prior art, it nevertheless still leaves something to be desired from several standpoints. For example, the trolley in the '228 patent is an assembly comprised of a box-like housing which hangs from a track by a pair of opposed rollers and is moveable between the ends of the track. In practice, because the trolley's weight is significant, it is necessary to control the trolley's speed as it travels forward upon a vehicle leaving the structure so as to prevent impact of the trolley with the front end of the track. Additionally, the exhaust blower of the '228 patent is activated in response to the sensation of increased pressure within the system as occasioned by the existence of exhaust fumes in the stack. As will be appreciated by those skilled in the art, at start-up, many diesel engines produce a great deal of smoke. Thus, a pressure activated exhaust blower, such as that used in the '228 patent, may not respond quickly enough to remove that smoke.